Wrinkled 2D hybrid heterostructures for stretchable and sensitive photodetectors

Abstract

Stretchable devices, including various electronic and optoelectronic devices, are an emerging class of future wearable technology that have attracted great attention. In particular, owing to their excellent flexibility, 2D materials, such as graphene and transition metal dichalcogenide (TMDC), are suitable for providing high stability and durability in the fabrication of stretchable devices. However, in terms of 2D-based optoelectronic devices, photoresponsivity is low due to the weak absorption of their small layer thickness. To overcome this shortcoming, herein, a highly sensitive and stretchable hybrid 2D heterostructured and wrinkled photodetector based on MoS₂ quantum disks and graphene is designed and demonstrated. Several factors are combined simultaneously to achieve stretchability and sensitivity, exceeding those designed with similar materials in most published reports. First, surface defects can be considerably reduced by doping suitable molecules on MoS₂ quantum disks, and the doped MoS₂ quantum disks show significantly enhanced absorption. Second, the photogenerated carriers in MoS₂ quantum disks can easily transfer to the graphene layer, which serves as a highly conducting channel. Third, in addition to exhibiting the stretchable capability of over 100%, the wrinkled structure is useful to induce the light trapping effect, generate more electron–hole pairs, and enhance photosensitivity. Moreover, strong photocurrent enhancement can be obtained after incorporating gold nanoparticles into the graphene/TMDC-based wrinkled heterostructured photodetectors owing to the surface plasmon resonance effect. Our results presented here are therefore useful for developing future stretchable and wearable electronics with ultrahigh sensitivity.